/*
 * The Apache Software License, Version 1.1
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 *    any, must include the following acknowlegement:  
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package com.lily.dap.service.core.Evaluator;

import java.util.Map;

import org.apache.commons.beanutils.PropertyUtils;

/**
 *
 * <p>This is the JSTL-specific implementation of VariableResolver.
 * It looks up variable references in the PageContext, and also
 * recognizes references to implicit objects.
 * 
 * @author Nathan Abramson - Art Technology Group
 * @version $Change: 181177 $$DateTime: 2001/06/26 08:45:09 $$Author: lzb $
 **/

public class VariableResolverImpl
  implements VariableResolver
{
	private Object context = null;
  //-------------------------------------
  /**
   *
   * Constructor
   **/
  public VariableResolverImpl (Object context)
  {
	  this.context = context;
  }
  
  public VariableResolverImpl ()
  {
  }
  
  public void setContext(Object context) {
	this.context = context;
  }

//-------------------------------------
  /**
   *
   * Resolves the specified variable within the given context.
   * Returns null if the variable is not found.
   **/
  public Object resolveVariable (String pName)
    throws EvaluatException
  {
	Object val = null;
	
	if (context instanceof Map) {
		Map dataMap = (Map)context;
		if (!dataMap.containsKey(pName))
			return null;
		
		val = dataMap.get(pName);
	} else {
		try {
			val = PropertyUtils.getProperty(context, pName);
		} catch (Exception e) {
			return null;
		}
	}
	
	return val;
  }
					
  //-------------------------------------
}
